A “bicycle” appearing in the tile of the invention is designed as a substantial “bicycle”. In particular, the “bicycle” of the invention is meant to include not only “bicycles” of the original meaning, but those two-wheeled vehicles that are not named “bicycle” because their wheels have diameters smaller than the minimum diameter required for wheels of standardized bicycles, or because they are provided with a power drive. The term “bicycle” thus meant is used throughout the specification and claims of this patent application.
As described in JP2001-328581A and JP2001-278160A, a number of folding bicycles, which can be folded small and preferably stored when not being used, have been proposed and introduced on the market.
Many of these folding bicycles have body frames, each being foldable between a front wheel and a rear wheel. When a folded part is assembled, in order to provide durability even when more than a certain weight is applied, the strength of the whole body is maintained by firmly tightening a special metal fitting upon assembling.
Further, other bicycles have foldable saddle posts and foldable stays for supporting the saddle posts. In order to provide these foldable parts with durability even when more than a certain weight is applied, the strength of the whole body is similarly maintained by firmly tightening special metal fittings upon assembling.
Therefore, the bodies become heavier and complicated operations are necessary during assembling and folding, posing a problem such that convenient use is difficult.